1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method for processing an image data based on information obtained from a plurality of viewpoints.
2. Description of the Related Art
As a method for checking an image using an image-capturing device after the image is captured, a method is currently known in which the captured image is checked by displaying it using an interface such as a so-called reproduction mode shifting button.
Furthermore, a method is known in which an image is captured by switching the mode to the image capturing mode corresponding to an object of interest at the time of capturing an image. For example, an optimum imaging condition is automatically set for capturing an image in such a manner that an image is captured in a portrait mode in a case where a human is the object of interest, while capturing an image in a landscape mode in a case where a landscape is the object of interest.
A technology in relation to the region segmentation by means of the graph cutting method has been developed in recent years (Y. Boykov and M. P. Jolly, “Interactive Graph Cuts for Optimal Boundary & Region Segmentation of Objects in N-D Images,” In International Conference on Computer Vision, volume 1, pages 105-112, July 2001). By means of this region segmentation technology, an image can be divided into regions by color to extract the amount of characteristic for each divided region, thereby recognizing the object for each region.
Furthermore, an image-capturing device employing a technique called the “light field photography” has been proposed in recent years (R. Ng, M. Levoy, M. Bredif, G. Duval, M. Horowitz, P. Hanrahan: “Light Field Photography with a Hand-held Plenoptic Camera”, Stanford Tech Report CTSR 2005-02(2005)). This image-capturing device is composed of an image capturing lens, a microlens array, an image capturing element, and an image processing unit, wherein a captured image data obtained from the image capturing element contains information on light intensity distribution on a light receiving surface as well as information on the traveling direction of the light. Then, the image processing unit can reconstruct an observation image from a plurality of viewpoints and directions.
One of the reconstruction processing is to adjust a focus after capturing an image (hereinafter referred to as refocusing) (Japanese Patent Laid-open No. 2011-022796, for example). An image-capturing device capable of refocusing after taking an image has been developed (hereinafter referred to as a light field camera). Furthermore, a technology has been developed in which a deep-focus image is generated from images from a plurality of viewpoints.
A current light field camera carries out the refocusing by a user tapping on a position desired to be focused on a touch-panel type display screen in a reproduction mode so as to display a combined image in which the focus is adjusted on the display screen.
The current light field camera requires the tapping operation on the display screen to adjust the focus upon refocusing at the time of shifting to the reproduction mode. Therefore, in a case where an image of a person, for example, is captured several times by a light field camera and then the captured image is viewed in the reproduction mode, a need for an extra work has been created for adjusting the focus by carrying out the tapping operation each time the captured image is switched to another one if the person is out of focus by default.